<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
	<title>盒子模型</title>
	<style type="text/css">
		div{

		width: 100px;
		height: 100px;
		border: 10px solid blue;
		padding: 40px;
		margin: 30px;	
		}

	</style>
</head>
<body>

<div>盒子模型</div>
</body>
</html>